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- UNITED STATES PATENT Tricia,"

NEIL MOOALLUM, or PHILADELPHI PENNSYLVANIA, Assic-Non, BY MESNE ASSIGNMENTS, TO THE LEEDS MA LYN, NEW YORK.

NUFACTURING COMPANY, OF EROOK- COMPOSITION To BE USED ASA PAll NT OR DYE.

To all whom it may concern.-

Be it known that I, NEIL McOALLUM, a citizen of the United States, residing at Germantown, in the county of Philadelphia and State of Pennsylvania, have invented a new and use ful Composition of Matter to be Used as a Paint or Dye, of which the following is a specifica tion.

The nature of my composition and the method or process of preparing the same are as follows: I take five parts of picric acid and thoroughly mix with three parts of flavine. To this compoundl add twelve parts of nitric acid of 36 strength, Baum. The resulting I 5 compound is then slowly boiled until the composition is evaporated to complete dryness. The resulting compound is a yellow dye, producing an unusually fast and permanent color, called echurine. v

The object of evaporating the fiavine and picric acid together with nitric acid, rather than first forming the compound whichis hereinafter designated nitro-flavine, and then using with picric acid, is that a more perfect mixture is produced by the method of evaporation and the resulting dye-stuff is more economically and conveniently manufactured.

The influence of the picric acid: The evaporation of picric acid, together with fiavine and 3o nitric acid, has no chemical influence on the resulting dye, as the picric acid can be sepa rated unchanged from the echurine; but the advantage of the procedure stated in this specification is twofold: First, an intimate 5 mediate mixture of the nitro-fiavine with the picric acid is thereby effected more perfectly than can be done by any mechanical means; and, second, a mass is obtained which can be easily removed from the vessel in which the 4o operation is conducted.

The infiuence of the nitric acid: The chemical change which occurs when nitric acid is i added to flavine and pioric acid is found in a very great resulting increase of temperature 4 5 and the evolution of dense fumes of nitrous acid. Flavine, whensimply treated with nitric acid, undergoes an entire chemical change,

as isshown by the increase of temperature and the evolution of nitrous fumes. The body ed August 14, 1883,

formed, in fact, is a nitro derivative of fla- 5o Vine, and is best distinguished under the name of nitr-o'flavine. It gives an entirely different dye-stuff from picric acid, which dyes Silk of a greenish-yellowcolor, while nitro-flavine dyes it of a salmon color; and when the nitro-flavine is added to picric acid in the manner described in the patent the resulting-dyestuff dyes the silk of the color of echurine. The body resulting from the treatment of fiavine with nitric acid and subsequent evapo- 6o rations is a nitro compound, (nitro-flavine,) and differs in every respectfrom the original body. Besides the nitro-fiavine, however, a small amount of the fiavine undergoes decom position by the action of the nitric acid, and a minute amount of picric acid is produced at the same time. Neither oiralic acid nor guercetinewere produced, as appears by a further examination of the bodies resulting from the action of nitric acid 011 the fiavine. dyeing properties of the compound produced by the action of the nitric acid on the flavine are due to nitro-flavine and not to gucrcetine,

as is shown by the absence of guercetine. The action of the nitric acid also is to increase the solubility of the compound, which appears from the fact that, while flavine isvery slightly soluble in water, echurine is. almost entirely so. There is no free nitric acid in the compound when prepared according to the specification, and the mass is evaporated to complete dryness.

As to the color of the dye: The color of thedye-stuff produced by the evaporation of nitric acid, picric acid, and flavine in the man- 8 5 ner hereinbefore described will vary between the salmon color due to nitro-flavine and the particular tint of yellow due to picrid acid,

, according to the relative amounts of flavine,

picric acid, and nitric acid originally em- 0 ployed and the thoroughness with which the chemical change due to evaporation to dryness is brought about. In case any flavine escapes conversion by nitric acid into nitrofiavine ,by the first evaporation, it is more completely changed by a second evaporation, and the resulting dye has a corresponding dif- A ference of tint, due to the larger percentage of The 70 nitro-fiavine. Under the name echurine all these various shades of color, varying from salmon to greenish yellow, and produced in WVhat I claim, and desireto secure by Let I 5 ter's Patent of the United States, is- The hereinbefore-described' composition of matter to be used as a dye, consisting of nitric acid, picric acid, and flavine, combined as hereinbefore set forth. 0

Dated July 7, 1882.

main MCOALLUM. [n s] \Vitnesses: I

A. MEINOKE, CHARLES H. WEIss. 

